op anderson



July 14, 1931. L, ARTHUR 1,813,900

IGNITION APPARATUS Filed Dec. 22, 1930 Jwuentoc Patented July 1 4, 1931 UNITED STATES PATENT OFFICE JAMES L. AR'THPR, OF ANDERSON, INDIANA, ASSIGNOR TO DELCO-REMY (l'OR-POR-ATION,

F ANDERSON, INDIANA, A CORPORATION OF DELAIVARE IGNITION APPARATUS Application filed December 22, 1930. Serial No. 504,050.

This invention relates to ignition apparatus for internal combustion engines and includes among its objects the provision 'of means whereby satisfactory ignition will be provided under all conditions of cranking and running and particularly when running at high speed and when cranking the engine with a starting motor using current from the same battery that supplies current for ignition purposes.

This aim of the present invention is accomplished in the disclosed embodiment thereof by a booster induction coil which is automaticallyv rendered operative during cranking of the engine to assist the regular ignition coil in providing satisfactory ignition. During the running of the engine the booster coil is non-operative until a predetermined high speed is attained or such a time when the closing period of the circuit interrupter timer contacts is so brief that the current which passes through the primary winding of the regular ignition coil is insufficient for satisfactory ignition.-

In the disclosed embodiment of the invention the automatic means for controlling the booster induction coil comprises a temperature responsive switch actuated by a thermostat heated by aheating coil, the current-in which is commensurate with the current in the primary winding of the regular ignition coil. Preferably the thermostat heating coil may be placed in series with the primary winding of the regular ignition coil.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of one form of the present invention is clearly-shown.

In the drawing:

The figure of the drawing is a wiring diagram embodying the present invention.

In the diagram designates the conventional ignition timer or circuit interrupter comprising a cam 21 which operates a lever 22 carrying a movable contact 23 cooperating with a stationary contact 24 grounded at 25. The contact 23 is urged toward the contact 24 by leaf spring conductor 26 connected with a condenser 27 grounded at 28 and connected with a terminal 29.

Terminal 29 is connected with the primary winding 31 and with the secondary winding 32 of an ignition coil 30. Secondary winding 32 is connected by wire 33 with the center contact 34 of an ignition distributor 35 which includes a rotor 36 connectible with any one of a circular row of distributor posts 37 connected with spark plugs 38.

The terminal 29 is connected With a booster induction coil 40 which in turnv is connectedwith a bimetallic thermostat blade 41 carrying at its free end a contact 42 en gageable with a contact 43 connected with a wire 44 in turn connected with a Wire 45 in turn connected by a switch 46 with a-battery 47 grounded at 48. The primary Winding 31 of the regular ignition coil 30 is connected by wire 49 with a heating coil 50 surrounding the bimetallicblade 41 and connected with Wire 45. Normally the blade 41 is so biased that the contact 42 will be in engagement with the contact 43. Therefore, when the switch 46 is closed the heater coil 50 will be 75 in series with the primary winding 31. of the regular ignition coil 30. Therefore, the thermostat blade 41 will be influenced by the current passing through the primary circuit of the ignition system.

During the cranking of the engine by the use of a cranking motor (not shown) using current from the battery 47, the voltage across the battery terminals Will be lower than during the running ofthe engine at ordinary speeds. Therefore, the current flowing through the primary 31 will be lower than that require-d for satisfactory ignition during running of the engine. During cranking, however, the current flowing through the heating coil is insuflicient to heat the bimetallic blade 41 sufficiently to cause it to be bowed upwardly and its contact 42 to separate from the contact 43. Hence, the booster induction coil 40 will remain in parallel connection with the ,primary Winding 31 of the regular ignition coil. Thus, when the contacts of the interrupter are separated, the energy stored in the booster coil 40 is released to supplement the energy of the regular primary'winding 31 to produce satisfactory ignition under cranking conditions. During the running of the engine up to a certain predetermined high speed, the de- 5 mand for cranking current from the battery 47 does not exist; hence the voltage of the battery or of an engine driven generator which charges it is at such a high value that suflicient current will flow through the primary winding 31 to produce satisfactory ignition without the aid of the booster coil 40. Under these conditions, the circuit to the booster coil 40 is automatically interrupted by reason of the fact that suflicient current flows through the thermostatic heating coil 50 to cause the thermostat to bow upwardly to separate the contact 42 from the contact 43. it

At speeds'higher than encountered during the normal running of the engine the contact closing period of the interrupter 20 may be too short to permit the building up in the primary winding 31 of a suificient current for satisfactory ignition. Under such conditions the current passing through the heating coil 50 is insufiicient to maintain the contact 42 out of engagement with the contact 43; hence the booster ignition coil 40 is again rendered operative to assist the regular ignition coil in providing satisfactory igniton at higher speeds.

In order to compensate for variations in temperature the block 60 which supports the thermostat blade 41 carries a similar bimetallic thermostat blade 61 arranged so that its steel side is adjacent the steel side of the blade 41 as indicated in the. drawing. By any suitable means (not shown) the blade 61 is thermally shielded from the effects of the heating coil 50 while both blades 41 and 61 are subjected to atmospheric temperature. The free end of the blade 61 is connected by link or strut 62 with the free end of the blade 41. In this way the position of the blade 41 does not change substantially due to changes in atmospheric temperature since any tendency to change by reason of a change in atmospheric temperature is resisted by an equal and opposite tendency of the blade 61 to change its position.

While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

.4 1. Ignition apparatus comprising in combination, an ignition coil including a primary winding, a current source, a circuit interrupter for controlling the passage of current from the source through the primary winding, a booster induction coil and a thermostat operated switch responsive to current 65 flowing through the primary winding for controlling the connection of the booster coil with the primarywinding.

2. Ignition apparatus comprising 1n combination, an ignition coil including a primary winding, a current source, a circuit interrupter for controlling the passage of current from the source through the primary winding, a booster induction coil, a switch for connecting the booster coil in parallel with the primary winding, and a thermostat blade responsive to current flowing through the primary winding for operating the switch.

3. Ignition apparatus comprising in combination, an ignition coil including a primary winding, a current source, a circuit interrupter for controlling the passage of current from the source through the primary winding, a booster induction coil, a switch for connecting the booster coil in parallel with the primary winding, a bimetallic thermostat for operating the switch, and a heater coil in series with the primary winding for heating the thermostat.

In testimony whereof I hereto aflix my signature.

JAMES L. ARTHUR. 

